Calcium Channel Blockers Flashcards
CCBs: Agents
Calcium Channel Blockers
There are 2 types-
» dihydropyridine: non-rate limiting»_space; bind to CC in blood vessels»_space; hypertension
» amlodipine, felodipine, nifedipine
> > non-dihydropyridine: rate-limited»_space; bind to CC in heart»_space; angina, supraventricular arrhythmias
diltazem, verapamil
CCBs: Indications
Hypertension»_space; reduced risk of MI
Angina
Ischemic heart disease
Supraventricular arrhythmias»_space; supraventricular tachycardia, atrial flutter, atrial fibrilation
CCBs: Mechanism of Action
Decrease Ca2+ ions entering vascular and cardiac cells»_space; reduced intracellular calcium
» relaxation of muscle cells»_space; vasodilation, reduced myocardial contraction
Dihydropyridine»_space; selective for vasculature
Non-dihydropyridine»_space; selective for heart»_space; rate-limiting
CCBs: Side Effects
Dihydropyridines: amplodipine, felodipine, nifedipine
» ankle swelling, flushing, headaches, dizziness, palpatations, oedema, postural hypotension
» vasculature selective»_space; vasodilation, and compensatory tachycardia
Non-dihydropyridines: diltiazem, verapamil
» constipation, RARE: bradycardia, heart block, cardiac failure
» cardiac selective»_space; reduce myocardial contraction
NOTE: DILTIAZEM is both cardiac and vascular selective»_space; side effect are all
CCBs: Contrainidications
Impaired ventricular function
Unstable angina
Aortic stenosis
CCBs: Interactions
CCB + BBs»_space; should not be used
» both are negatively chronotropic (heart rate) and negatively inotropic (contractility)
> > cause heart failure, bradycardia, asystole
CCBs: Monitoring
Clinical efficacy monitoring-
Hypertension: regularly check BP
Angina: inquire about chest pain
Arrhythmias: check ECG
Start at 5mg and titrate upwards until target met
» regularly monitor
